Top 10 Media Buying Agencies in California (2026)
The top 10 media buying agencies in California for 2026, ranked by Growth Partner Confidence Score with cited public evidence for every pick.
Updated July 27, 2026 · Compiled and reviewed by Growth Partner Index Editorial Desk
This shortlist ranks the 10 highest-scoring media buying agencies working in California, drawn from the 478 agencies currently in the Growth Partner Index. Ranking is by Growth Partner Confidence Score, which is built from public evidence only.
The agencies below are based in New York, NY & Los Angeles, CA, Irvine, CA, Los Angeles, CA, El Segundo, CA. Each entry links to a full profile with the score breakdown, the sources behind it, disclosed budget band, and the services the agency actually staffs for.
Use it as a starting shortlist, not a verdict. A high score means the public evidence is strong; it does not mean the agency is the right fit for your budget, category, or measurement maturity.
The shortlist
Ranked by Growth Partner Confidence Score
- 1
inBeat is a performance creative agency that turns UGC and influencer partnerships into high-converting ads, with expertise in paid media and growth marketing.
Full profileVisit website$250k–$1M/mo
- 2
Directive Consulting is a growth marketing agency based in Irvine, CA working with B2B SaaS / Technology and Information technology brands. Publishes 4 case studies with named clients and measurable outcomes, including Case Status, Seagate Technology, DBT (dbt Labs). Rated 4.8 from 56 reviews on clutch.co.
Full profileVisit website$10k–$50k/mo
- 3
Darkroom is a growth marketing agency based in Los Angeles, CA working with Home Goods and Fashion & Apparel brands. Publishes 3 case studies with named clients and measurable outcomes, including OLIPOP, Crate & Barrel, Everlane.
Full profileVisit website$50k–$250k/mo
- 4
Single Grain is a growth marketing agency based in Los Angeles, CA. Publishes 3 case studies with named clients and measurable outcomes, including SmartRent, LS Building Products, Simon Pearce. Rated 4.8 from 11 reviews on clutch.co.
Full profileVisit website$10k–$50k/mo
- 5
Eboost Consulting is a growth marketing agency based in El Segundo, CA working with eCommerce/DTC and B2B brands. Publishes 1 case study with named clients and measurable outcomes, including Itochu Descente. Rated 4.9 from 15 reviews on clutch.co.
Full profileVisit websiteNot disclosed
- 6
Common Thread Collective is a growth marketing agency based in Costa Mesa, CA working with Ecommerce / DTC and Apparel brands. Publishes 3 case studies with named clients and measurable outcomes, including Dorsal, Igloo, Born Primitive.
Full profileVisit websiteNot disclosed
- 7
Wpromote is a growth marketing agency based in El Segundo, CA working with B2B and Financial services brands. Publishes 2 case studies with named clients and measurable outcomes, including Whirlpool, Klipsch.
Full profileVisit websiteNot disclosed
- 8
Amazon Growth Lab is a growth marketing agency based in Culver City, CA. Publishes 3 case studies with named clients and measurable outcomes, including Ernst Grain, Mavi Jeans, Ray-Ban. Rated 4.9 from 35 reviews on clutch.co.
Full profileVisit websiteNot disclosed
- 9
Open Influence is a growth marketing agency based in Los Angeles, CA working with Financial Services and Alcohol brands. Publishes 3 case studies with named clients and measurable outcomes, including Dave, BBVA, NerdWallet.
Full profileVisit websiteNot disclosed
- 10
KlientBoost is a growth marketing agency based in Costa Mesa, CA working with SaaS/B2B and E-commerce brands. Publishes 2 case studies with named clients and measurable outcomes, including Fashionphile, Segment.
Full profileVisit websiteNot disclosed
How we picked
Agencies qualify for this list by working in media buying and, for location lists, being headquartered in California. Ranking is by Growth Partner Confidence Score, which is built from public, citable evidence only.
Read the full Growth Partner Confidence Score methodology, or submit a correction if something here is wrong.
Frequently asked questions
- Who is the #1 media buying agency in California in 2026?
- inBeat ranks #1 among media buying agencies in California for 2026 with a Growth Partner Confidence Score of 88.5/100. inBeat is based in New York, NY & Los Angeles, CA and is best suited to cpg, ecommerce, technology, travel, and health brands. Directive Consulting (77/100) ranks second.
- How were these agencies selected?
- Every agency on this list is scored against the same seven-pillar Growth Partner Confidence Score: proof of outcomes, category fit, creative-media integration, reputation, operating maturity, buyer fit, and freshness. Scores are built only from public, citable evidence such as case studies, press, and interviews. Placement cannot be purchased, and sponsored listings are labelled and never re-ranked.
- What should I look for when choosing a media buying agency?
- Ask about account hygiene practice, server-side conversion tracking, and incrementality testing. Ask who touches the account daily and how often that person changes. Beyond that, confirm the budget band matches yours and that the senior operator named in the pitch is the person who will actually run the account.
- How much do media buying agencies charge?
- Fee structures are usually a flat retainer of $5k–$30k/mo or 8–15% of managed media spend, with the percentage model taking over above roughly $250k/mo in spend. Every profile in this index lists the agency's disclosed budget band so you can filter before the first call.